feat: new entrypoint script, calls start script which in turn has case statement

to be more flexible passing commands or executing a script when staring container
by default will start a shell
can map host user set of to be shared directories in the container (via volumes) if HOST_MAP is set

src/common/scripts/container.env

@@ -0,0 +1,2 @@
+export SHARED_DIRS="/shell /opt /data"
+export INITIAL_DIR=/opt/scripts

src/common/scripts/entrypoint.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+export SCRIPTS_DIR="$(dirname $(realpath "${BASH_SOURCE:-$0}"))"
+# echo arguments in entry $@
+# execute the start script in a login shell so that the uci shell will be sourced 
+# see https://stackoverflow.com/a/1711985/4695378 passing $@
+/bin/bash -l -c '${SCRIPTS_DIR}/start.sh $@' $0 "$@"

src/common/scripts/host-id-map.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+source $SCRIPTS_DIR/container.env
+if [[ $HOST_MAP ]]; then
+  echo changing ownership of $SHARED_DIRS to $HOST_MAP
+  $([[ ! $EUID -eq 0 ]] && echo sudo) chown -R $HOST_MAP $SHARED_DIRS
+fi 

src/common/scripts/start.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+# echo arguments in start script:  "$@"
+source $SCRIPTS_DIR/container.env
+source $SCRIPTS_DIR/host-id-map.sh 
+case "$1" in
+  shell_update)
+  echo updating shell repos
+  ;;
+  cmd)
+  shift 1
+  "$@"
+  ;;
+  script)
+  shift 1
+  module_load path
+  script=$([[ $(isAbsPath $1) ]] && echo $1 || echo $SCRIPTS_DIR/$1)
+  shift 1
+  /bin/bash $script "$@"
+  ;;
+  *)
+  /bin/bash -c "cd ${INITIAL_DIR:-$HOME}; exec bash -l"
+esac